In recent years, as the eating habit of Japanese people has changed and as air pollution and infections have decreased, the incidences of various allergic diseases typified by pollinosis, food allergy, atopic dermatitis, bronchial asthma and contact hypersensitivity are increasing rapidly, and so are the numbers of patients suffering from osteoarthritis and other bone/joint related diseases as aging accelerates in the Japanese society.
According to the 2003 Survey of Health and Welfare compiled by the Ministry of Health, Labor and Welfare (MHLW), more than forty million people accounting for about a third (35.9%) of Japan's population, irrespective of sex and age, present with allergic symptoms in either the skin, respiratory organs, or the eye and nose.
Data by disease can be found in the 2010 Report of Akazawa Group in Scientific Research under MHLW grant; in the 2005-2008 period, the prevalence of infantile bronchial asthma was 13.8% at ages 6-7, 9.5% at ages 13-14, and 8.3% at ages 16˜18 whereas the prevalence of bronchial asthma in adults (aged 20-44) was 5.4%. As regards allergic rhinitis and pollinosis, the 2009 Clinical Guideline for Nasal Allergy reports that in the 1998-2008 period, the overall prevalence of allergic rhinitis increased from 29.8% to 39.4% and that of Japanese cedar pollinosis increased from 16.2% to 26.5%. Speaking of atopic dermatitis, its prevalence was 13.2% at age 3, 10.6% in sixth graders at elementary school, 9.4% in the twenties, 8.3% in the thirties, 4.8% in the forties, and 2.5% in the fifties to sixties (the 2008 Clinical Guideline for Atopic Dermatitis).
Allergic diseases occurring in the daily life of Japanese people are one of the major factors that lower their quality of life (QOL). According to the 2003 MHLW Survey, idem, approximately a half (53.4%) of patients complaining of allergic symptoms in respiratory organs responded that they “could not sleep well” and approximately 40% (37.2%) of patients suffering allergic symptoms in the eye and nose responded that they “could not concentrate on work, housekeeping, or schoolwork.”
Conventional treatments of allergic diseases have involved medication of drugs such as antihistamines and steroids as part of symptomatic therapy but a problem with these drugs is that they cause serious side effects if administered for an extended period of time. It has, therefore, been desired to develop an ingredient that can be manufactured in a safe and easy way and which is capable of alleviating, suppressing or preventing allergic symptoms, with the additional feature that it can be integrated into the daily dietary life.
As aging accelerates in the Japanese society, bone/joint diseases such as osteoarthritis and osteoporosis are also increasing in number year by year. According to the 2007 National Livelihood Survey compiled by MHLW, two major causes for needed care were joint disease and fracture/falling which accounted for 20.2% (ranking first) and 12.5% (ranking fourth), respectively, of the persons in need of support, whereas they accounted for 9.4% (ranking fourth) and 8.4% (ranking fifth), respectively, of the persons in need of nursing care; thus, bone/joint diseases are one of the major factors that degrade the activities of daily living (ADL) and QOL of Japanese people. In 2007, the Japanese Orthopaedic Association proposed a concept called “locomotive syndrome” which refers to either a state that requires nursing care or one presenting a high risk for the need of nursing care, both due to a locomotor disability and in 2009, Yoshimura et al. at the University of Tokyo Hospital conducted a large-scale resident's cohort study called Research on Osteoarthritis/Osteoporosis Against Disability (ROAD) and reported that as many as forty-seven million people (aged 40 and above) were found to have a locomotive syndrome. Obviously, there exists an urgent need to cope with allergic disease and bone/joint disease because, for one thing, they are quite serious diseases that can potentially degrade ADL and QOL as well as shortening the health span and, for another thing, the ever-growing medical costs must be reduced.
Under these circumstances, active efforts are being made to develop pharmaceutical drugs and food ingredients that can alleviate, suppress or prevent allergic disease and osteroarthritis. Food ingredients so far reported to have an allergy suppressing action include, for example, Lactobacillus (Patent Document 1), royal jelly (Patent Document 2), fucoidan which is a water-soluble polysaccharide component in seaweeds (Patent Documents 3 and 4), and alginic acid (Patent Document 5).
It is known that the degranulation reaction of mast cells or basophiles is critical to the onset of various allergic diseases including pollinosis, atopic dermatitis, allergic rhinitis, and allergic conjunctivitis. When an allergen invades the body, the production of an allergen-specific antibody is induced and the allergen-specific antibody produced binds to the surface of a cell such as a mast cell or a basophile, whereupon sensitization is established. When the body is invaded again by an allergen, it binds the allergen-specific antibody on the surface of the mast cell or basophile, whereupon a granule containing a chemical mediator is released out of the cell, triggering an allergic reaction such as enhancement of vascular permeability or constriction of bronchial smooth muscle. Hence, one effective way to suppress various allergic diseases including pollinosis, atopic dermatitis, allergic rhinitis, and allergic conjunctivitis is by suppressing this degranulation reaction.
Food ingredients so far reported to have the degranulation suppressing action include, for example, a plant (galena) extract (Patent Document 6) and phycoerythrin found in red algae (Non-Patent Document 1).
Furthermore, a recent study reported that a glucosamine hydrochloride having an osteroarthritis suppressing action exerted a degranulation suppressing action and also reported was an osteroarthritis suppressing effect mediated by the degranulation suppressing action (Non-Patent Document 2). These results suggest that by investigating the degranulation suppressing action, not only the effect for suppressing allergic disease but also the effect for suppressing osteroarthritis can be verified.
Aside from the glucosamine hydrochloride, various other ingredients have been reported to have the osteroarthritis suppressing action and they include a chondroitin sulfate (Non-Patent Documents 3, 4, 5, 6, 7 and 8) and plant extracts such as those of a plant of the family Compositae (Patent Document No. 7) and spices (Patent Document 8).
Chlorophyll which is a photosynthesis pigment typically contained in plants may be defined as a metal complex of cyclic tetrapyrrole coordinated with Mg or Zn and while it is primarily used as a colorant and food additives that take advantage of its nature as pigment, chlorophyll's recent medical application in photodynamic therapy (PDT) is worth mention (Non-Patent Document 9). In this connection, chlorophyll of high purity is extracted from plants, algae, etc. using organic solvents, etc. and is subsequently separated and purified using an absorption photometer, high-performance liquid chromatography, etc. (Non-Patent Documents 10, 11, and 12). Concerning chlorophyll's functionality, a report was made of a chlorophyllin copper complex as a chlorophyll analog having an antioxidization-based antimicrobial, anticancer, antiatherosclerotic, antipsoriatic and other beneficiary actions (Non-Patent Document 13); however, no report has yet been published about the degranulation suppressing effect of chlorophyll that contributes to allergy suppression as by suppressing vascular permeability or to osteroarthritis suppression.